Arterial stiffness in persons with paraplegia

Background: Arterial stiffness recently has been identified as an independent risk factor for cardiovascular disease. An accurate and noninvasive estimate of arterial stiffness can be made through close examination of the pulse wave contour, and is expressed as the augmentation index (AI). Increased stiffness is associated with increased systolic blood pressure (SBP), pulse pressure, and reduced baroreceptor sensitivity. The purpose of this study was to compare the common carotid Al in participants with paraplegia vs able-bodied controls as well as compare group differences for blood pressure while supine and in response to gravitational stress. Participants: Study participants were 19 healthy individuals with paraplegia (below T6) and 9 able-bodied controls matched for age, height, and weight. Methods: An electronic tilt table was used for testing responses to gravitational stress at 4 angles ( -10degrees, 10degrees, 35degrees, and 75degrees). Al was assessed at each angle of tilt using an externally applied high-fidelity strain-gauge transducer placed over the right common carotid artery. Results: Al was augmented in the group with paraplegia compared with the able-bodied group (8.0 +/- 3.9 vs 6.7 +/- 2.8, respectively; P < 0.05). Supine blood pressure and the SBP response to tilt did not differ between the groups, and there were no tilt-angle effects on SBP. Conclusion: In normotensive persons with paraplegia, Al was increased significantly compared with matched able-bodied controls, which may suggest the premature development of arterial disease in this population.